Bridge-building apparatus



Deg. 16, 1930. V.I B. EDWARDS ET AL 1,735,023

BRIDGE BUILDING APPARATUS Filed Jan. 31, 1930 4 Sheets-Sheet l WITNESS INVENTORS I Z fibww 1 m m I INVENTORS Dec. 16, 1930.

v. B. EDWARDS ET AL B RI DGE BUILDING APPARATUS 4 Shts-Sheet 2 Fild Jan. 31, 1950 a any Wen/3.6m

Dec. 16, 1930. v. B. EDWARDS ET AL 1,735,023

BRIDGE BUILDING APPARATUS F'i-led Jan 31, 1950 4 Sheets-Sheet s wn'uss s 3 v. B. EDWARDS ETAL 1,735,023 I BRIDGE BUILDING APPARATUS 31, 1930 v 4 Sheets-Sheet 4 Filed Jan.

INVENTORS Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE VERE 3. EDWARDS, OI MOON TOWNSHIP,'ALLEGHENY COUNTY, AND GEORGE F. WOLFE,

]? CORAOPOLIS, PENNSYLVANIA,

ASSIGNORS TO THE DRAVO CONTRACTING COI- PANY, A CORPORATION OF PENNSYLVANIA BRIDGR-BRILDING APPARATU S Application filed January 31, 1930. Serial No. 424,888.

them it is held and-sustained. The bridge cables, of which commonly there are two, although the number may be varied, are formed each of a plurality of strands, seven in number for example, although there maybe more or less; and each strand consists of a bundle of single wires gathered and bound, and ordinarily approximately circular in cross-sec- I tion. The strands are made up, and after making up are brought to place from one end of the bridge over the towers to the other end, and each strand is separately anchored. Theseven strands, more or less, of each'cable are assembled, squeezed to a compound bundle,-

which also in cross-section is approximately circular; and, at the end of the bridge-building operations, when the cables have been put under tension carrying the full weight of the structure, the cables are closely wrapped in wire. This invention has particularly to do with the bringing of the madesup cable strands to place.

In the accompanying drawings Fig.1 is a diagram, showing in side elevation a suspension bridge in course of erection. Figs. II and III are views to larger scale, showing in side elevation the anchorages at the two ends of. thebridge. Figs. IV and V are views in front and side elevation, showing fragmentarily the upper portion of a bridge tower and .the false work upon the tower, employed in the placement of the cables. Fig; Va is a view in side elevation of a detail, shifted aside from its place in Fig. V. Figs. VI and VII are views to still larger scale, and Fig. VII to scale larger than Fig. VI, showing in side elevation and in transverse vertical section a certain guide which is included in the showhanging cables the accurately determined ing of Figs. IV and V. In Fig. VII a certain carriage is shown in position upon the guide. Figs. VIII and IX are views showing in front and side elevation the carriage just alluded to, which carriage, provided in considerable numbers, is employed in bringing the cable strands to place.

Referring first to Fig. I, the anchorages on the opposite river banks are indicated at. 1 and 2. This particular bridge structure includes also a succession of piers '3 for carrying the roadway at one end, because at this end the anchorage is necessarily low, but it will be understood that such piers are not essential features of the bridge type. Between the two anchorages stand the towers 4 and 5 of which in this case there are, as is usual, two.

The towers, being erected, are held firmly in position to endure the particular and relaunderstood, are temporary and, when the "cables have been brought to place, they are'removed. InFig. I the dotted line 7 indicates the position to which the cable strands are initially brought, and the full line, 8 indicates the ultimate position of the bridge cables when completed and subjected to the load of the structure. In Figs. IV and V the tower 4 is shown to be surmounted with a saddle 9-,- in which, as is diagrammatically indicated 1n Fig. IV, the completed cable eventually rests. From the saddles 9 on the bridge towers the cables eventuall hang.

The false work erected upon the tower is a suitable framework in which are firmly carrled a palr of guides 10 and a pulley hoist 11. The guides 10, as is best shown in Fig. IV, stand apart on either side of the vertical plane which is central with respect to saddle 9 and which is longitudinal of the bridge structure as a whole.

Themore minute formation of each guide 7 will be understood on considering Figs. VI and VII. Each consists of two parallel plates 12 with arc-shaped upper edges, standing vertically, and spaced apart at an interval, and carrying journalled between them a succession of idly turning, grooved sheaves 13.

Upon the saddle 9 a block 14 is removably mounted, and in it a grooved sheave 15 is rotatably borne. This block with its sheave is a temporary element, used in building, but ultimately removed with the other false work.

Through the guides 10, from anchorage to anchorage, extend two parallel, temporary wa -cables 16, spaced apart at an interval delihed by the spacing of guides 10. Within the guides these way-cables rest upon the sheaves 13, as clearly appears inv Fig. VII. The way-cables are brought to place and secured and, subject to adjustment, remain in position until all the cable strands have been brought to place and secured, and then, but not until then, they are removed.

The carriage, illustrated in Figs. VII,VIII, and IX, includes an essentially U-shaped frame 17 This frame carries, journalled externally upon its two arms at their upper ends, the sheaves 18, and preferably a sheave 19 also, which sheave 19 is journalled internally between its arms near the bendof the U. Externally, at the bend of the U, the frame 17 is equipped with a clamp 20, by which engagement with a back-hauling line may be made and broken at will. The groove-to-groove interval at which the sheaves 18 stand apart is the interval betweenthe grooved sheaves of the two parallel guides 10, 10. The breadth of each sheave 18 is such as to span the space at which the two plates 12 of each guide stand apart. The

proportions of the frame are such that when in the load-carrying position, which is the position shown in Fig. VIII, the load resting on sheave 19 is at very considerably lower level than the way-cable's 16, upon which the sheaves 18 make bearing. In the case in hand, the interval between the way-cables being 10 inches, more or less, the load is advantageously carried at an interval ,of 20 inches, more o'r less, below the way-cables. This interval last defined is somewhat less than the interval vertically at which the guides 10 stand above the sheave 15.

In preparation for the placement of the cable strands, the false work is erected upon the towers, as shown in Figs. IV and 'V, and the way-cables are brought to position and secured attheir ends to the anchorages, as shown in Figs. II and III. Each cable strandis gathered and shaped and provided at'its ends with loops fitted withshoes for making it fast in the anchorages, and initially lies in its entirety .at the place of spinning, which is usually on the ground or above the ground at or near the river bank, as'

seen at the left inFig. I An engine with a winding drum is stationed on the right or opposite bank of the river, and from this winding drum a messenger line 21 is carried over the sheaves 15 upon the towers and is secured to the looped end of the cable strand. The cable strand is designated 22, and in Figs. II and III is indicated by a dotted line. By the winding of the messenger line upon the power-driven drum the cable strand is hauled to place. To the messenger line 21, at the end to which the cable strand is secured, a back-hauling line 23 is secured.

As the cable strand 22 advances from the bridge-end to the left, carriages are, by clamps 20, secured at intervals to the backhauling line 23, the sheaves 18 of each carriage bearing upon the way-cables 16, and the cable strand within the U-shaped frame and resting upon the sheave 19 of the carriage. This assembly will be manifest on comparing Figs. II and VIII, and it will be perceived that haulage upon messenger line 21 causes the string of carriages bearing the load of the cable strand to run along the way-cables.

The messenger line normally rests upon the sheaves 15, and the cable strand as it is being brought to place rests intermittently upon the sheaves 15, but, in haulage, as each carriage in turn approaches the tower, it raises the strand from engagement with sheave 15 and sustains it, hung from the guides 10. Accordingly, in the course of building, the cable strand at the high points is borne-alternately by sheaves 15, and by guides 10.

In passing the guides the sheaves 18 of the carriages, which elsewhere run upon the waycables 16, run upon the dges'of the plates 12 of the guides, while the way-cables, unburdened at that point, rest upon the sheaves 13 of the guides.

When a cable strand has been brought to position and its free ends have been secured to the anchorages on the two sides of the river, the strand is lifted .by the, chain blocks situated on the towers, as is indicated in Fig. V by the numeral 11, to allow the carriages 17 on their return to pass above the rollers 15. The way-cables 16 then are slackened, to such extent that the cable strandbecomes in part orentirely self-sustaining, with only sufficient load remaining on the carriages to prevent their overturning or with the strand in such position as to prevent overturning when they (the carriages) are returned from right to left. When thishas been done the backhauling line 23 is by suitable means drawn back from rightto left, and by such drawing back of the line'23 the messenger line 21'is returned across the river. As the back-hauling lineis drawn back from right to left across the river, the carriages one by one, at the left-hand end ofthe gaged, and whenthe return of the back-hauling line has been completed, thecable strand remains, supported from the blocks and the ,anchorages, entirly self-sustaining. The el ain blocks in the tower superstructure's' bridge, are disenthen are lowered and; the. cable strand issheaves 15 and the false work over the towers are permanently removed.

Temporary supports 24 and 25 for the waycables 16, the latter equipped with a sheave 26 for the messenger line 21, are obviously advantageous. The ultimate position of the anchored cable strand is in Figs. II and III- indicated by the-dotted line 27; and it will be apparent that, when the last cable strand has been placed and anchored, the messenger line 21, the back-hauling line 23, and the waycables 16 may be taken away, and that then these temporary supports 24 and 25 will be removed.

We claim as our invention:

1. Bridge-building apparatus adapted for use in cooperation with bridge towersand two anchorages, such apparatus including adjustable doubleway-cables, a plurality of carriages movable upon said way-cables, each carriage adapted to receive a cable-strand and provided-with a clamp, a messenger line capable of being'drawn to and fro over the bridge towers'and adapted to engage at one end a cable strand and to draw the cable strand to position between the anchorages and upon the towers, and a back-hauling line adapted to be engaged by the carriage clamps.

2. Bridge-building apparatus adapted for use in co-operation with bridge towers and two anchorages, such apparatus including a sheave and a pair of guides borne by each bridge tower, the guides spaced above the sheave, a pair of adjustable way-cables borne by said guides, a plurality of carriages movable upon said way-cables, each carriage adapted to receive acable-strand and being provided with a clamp, a back-hauling line adapted to be engaged by the carriage clamps, and means for hauling a carriagesustained cable-strandto its position of rest with respect to the anchorages, and temporarily supported above the tower sheaves.

3. In combination with a bridge tower I equipped with a cable-carrying saddle, false work borne by the tower including a strandcarrying sheave, apair of guides arranged at an interval above said sheave, and hoisting apparatus, a pair of way-cables resting in said guides, a plurality of strand carriages movable upon said way-cables, a back-haul line to which said carriages are removably' attachable, and means for hauling a carriageborne strand to place.

' 4. In. false work upon a bridge tower a 4 I sheave rotatable upon a horizontal axis arranged transversely upon the tower, a pair of guides arranged at an interval above said sheave spaced apart and symmetrically arranged with respect to the vertical mid-plane, perpendicular to the axis of the sheave, each guide including two vertically extendin plates with arc-shaped upper edges an sheaves journalled in the space between and presenting a bearing face at a lower level than the plate edges, and hoisting means adapted to move a load vertically in the aforementioned mid-plane of the sheave, together with a pair of way-cables resting on the sheaves within the guides and a plurality of strand carriages equipped each with a seat for a cable strand and with a pair of grooved traction wheels-spaced apartat an interval corresponding to that between the guides, the rims of each wheel being, spaced apart at a distance equal to the spacing apart of the plates of which each guide is composed, the vertical distance between the strand seat of the carriage and the running face of the traction wheels being less than the vertical distance between the sheave and the pair. of guides first mentioned.

5. Bridge-building apparatus adapted for use in cooperation with bridge towers and two anchorages, such apparatus including double way-cables, a plurality of carriages movable upon said way-cables, each carriage adapted to receive a cable-strand, a messenger line capable of being drawn to and fro over the bridge towers and adapted to engage at one end a cable strandand to drag the engaged cable strand to position between the anchorages and upon the towers, and a line engaged by said carriages.

6, In false work upon a bridge tower-a sheave rotatable upon a horizontal axis ar-,

ranged transversely upon the tower, a pair of guides arranged at an interval above said sheave, spaced apart, and symmetrically arranged with respect to the vertical mid-plane perpendicular to the axis of the sheave, a pair of wa -cables resting upon said guides, a plurality of strand carriages each including upper lateral sheaves adapted alternately to rest upon and to travel upon said pair of guides and said pair of way-cables and a lower central ,strand support, the vertical distance between the strand seat of the-carriages and the runnin faces of the upper lateral sheaves thereo being less'than the vertical distance between the said sheave upon the tower and the said uides arranged above the sheave, together Wlth a messenger In testimony whereof wel have hereunto I set our hands. 7

' 'VERE B. EDWARDS.

GEORGE F. WOLFE. 7 

